Lectotype optimization of offshore platforms by use of three-scale fuzzy analytical hierarchy process

A Three-Scale Fuzzy Analytical Hierarchy Process (T-FAHP) is proposed by in troducing the Three-Scale Analytical Hierarchy Process (T-AHP) and the trap ezoid fuzzy number. A multi-objective optimization model based on the T-FAH P is presented subsequently, in which many factors influencing the lectotyp e of offshore platform are taken into account synthetically, such as the or iginal investment, the maintenance, cost, the ability of resisting fatigue and corrosion, the construction period, the threat to the environment, and so on. With this method, the experts can give the relatively precise rankin g weight of each index and at the same time the requirement of consistence checking can be met, The result of a calculation example shows that the T-F AHP is practical.